Guiding means for movement of solid materials



April 3, 1951 c. H. PRESCOTT, JR

GUIDING MEANS FOR MOVEMENT 0F SOLID MATERIALS 2 Sheets-Sheet 1 Original Filed Sept. 2, 1944 INVENTOR. CHAEL 55 f1 Pee-560 7'7- Je,

Wh wm ATTORNEY.

Apr? 3, 1951 c. H. PRESCOTT, JR

GUIDING MEANS FOR MOVEMENT 0F SOLID MATERIALS 2 Sheets-Sheet 2 Original Fild Sept. 2, 1944 all!!! INVENTOR. CHAELE-S f7. Peascorr Je.

ATTORNEY.

Patented Apr. 3, 1951 GUIDING MEANS FOR MOVEMENT OF SOLID MATERIALS Charles H. Prescott, Jr., Berkeley, Calif., assign?- or to the United States of America as represented by the United States Atomic Energy Commission Original application September 2, 1944, Serial No.

552,556. Divided and this application November 2, 1945, Serial No. 626,389.

2 Claims.

This invention relates to apparatus for use in connection with packaging and/or closing, in the absence of air, receptacles containing material that is rapidly decomposed or otherwise affected deleteriously when exposed to atmospheric conditions. More particularly, it appertains to certain implements useful in connection with vacuum apparatus adapted for the purification of chemical compounds such as uranium chlorides that must be handled in the absence, or substantial absence, of air. This application is a division of my prior copending application Serial No. 552,556, filed September 2, 1944, and contains claims directed to certain adjuvant apparatus elements that have proved to be particularly useful in conjunction with the method and apparatus forming the subject matter of the prior application.

The invention has for an object the provision of adjuvant apparatus elements useful in connection with the vacuum packaging of a hygroscopic material such as hygroscopic uranium compounds. Other objects are to provide certain apparatus elements useful in conjunction with apparatus for purifying and packaging uranium compounds under vacuum conditions, and to seal hermetically vacuum containers charged with uranium compounds. Additional objects are to provide certain apparatus elements useful in conjunction with apparatus adapted to isolate a uranium chloride in a vacuum, to sublime a uranium chloride in a vacuum, to purify a uranium chloride in a vacuum, and to store a uranium chloride in a vacuum. A general advance in the art and other objects that will appear hereinafter are also contemplated.

In accordance with this invention, an apparatus has been originated for packaging a volatile, hygroscopic compound, such as a volatile, hygroscopic uranium compound, comprising subliming a hygroscopic uranium compound, condensing the sublimed compound, charging a container with the sublimed compound, and hermetically sealing the container, all of the operations being conducted without exposing the hygroscopic uranium compound to the atmosphere. Uranium compounds that are suitable for treatment in this manner are uranium hexachloride, uranium tetrachloride, and the like.

An apparatus suitable for purifying and packaging the hygroscopic uranium compound comprises a subliming chamber, a condensing cham ber joined thereto, a storage receptacle and a conduit connecting the condensing chamber and storage receptacle, means for maintaining a vacuum in the apparatus, means for heating the subliming chamber whereby the uranium compound is sublimed into the condensing chamber where it is condensed, means for moving the sublimed and condensed uranium compound into the conduit and the storage receptacle, and means for hermetically sealing the charged storage receptacle. The present application is concerned more particularly with certain adjuvant apparatus elements that have been found to be particularly well adapted for assisting in maintaining the proper movement of solid material, comprising the uranium or other compound, through the apparatus, and particularly through the subliming and/or condensing chamber.

It has been found that under the thermal conditions obtaining in the subliming and/or condensing chambers, the uranium or other compound forming the charge material and/or the uranium or other compound forming the sublimed and purified product frequently tends to adhere tightly to the wall of the subliming and/or condensing chambers. Moreover, the uranium or other compound, particularly that comprising the purified product, is sometimes present in the apparatus in the form of lumps or granules and/ or conglomerated masses that require to be broken up if the broad objects of the apparatus are to be attained in the most preferred manner. Furthermore, it appears that the charge material itself that is introduced into the subliming chamber sometimes tends to conglomerate, due to the thermal conditions obtaining within the subliming chamber and/or possibly in some cases due in part to a slight residual moisture content in the charge material.

Accordingly, certain adjuvant apparatus elements have been fabricated particularly with a view toward the more efiicient handling of the material undergoing processing in the subliming and/or condensing chamber of the receptacle charging apparatus forming the subject matter of the above-mentioned copending application Serial No. 552,556. As will appear more fully hereinafter, these adjuvant apparatus elements are materials-handling elements so arranged and employed in connection with the apparatus that they are operable from outside the apparatus through appropriate Wilson seals, thereby permitting them to be operated at will from without the apparatus at the convenience of the operator, without at the same time making it necessary to break the relatively high vacuum that is maintained in the interior of the apparatus. 3

How the foregoing objects and related ends are accomplished will be apparent from the following description including the principle, the organization and various embodiments of the invention, and the best mode contemplated for carrying out the same. This description is amplified by the accompanying drawings, in which:

Figure 1 is a fragmentary side view, in elevation, of the combined charge purifying and receptacle filling and sealing apparatus embodying the features of the invention.

Fig. 2 is a fragmentary view, in plan, of the end of the material moving device employed in the condensing end of the apparatus of Fig. 1.

Fig. 3 is a side view, in elevation, of the device of Fig. 2.

Fig. 4 is an end View, in elevation, of the device of Fig. 2.

Fig. 5 is a fragmentary view, in plan, of the end of the material moving device employed in the feeder end of the apparatus of Fig. 1.

Fig. 6 is a side view, in elevation, of the device of Fig. 5.

Fig. 7 is an end view, in elevation, of the device of Fig. 5.

Fig. 8 is an enlarged fragmentary view, partly in section, of a portion of the apparatus of Fig. 1, illustrating the closing hood and a storage receptacle secured thereto, as well as a typical Wilson seal arrangement by which the material moving devices may be manipulated from without the apparatus without at the same time breaking the vacuum existing within.

Referring now to Figs. 1 to 8 of the drawings, there is illustrated a purifying and packaging apparatus constructed largely of glass and comprising a hopper Ii! in which the material to be processed is placed before the purification operation is started. A hopper having a capacity of about one liter is suitable. This hopper has a conduit 12 through which it is filled with raw material, a tubular extension l4 designed to receive a conventional Wilson seal 56 having a vacuum testing connection tube l8, and a duct for connection to a vacuum-producing apparatus (not shown). A removable plug 22 fitting tightly in the conduit 42 seals this part of the apparatus against the atmosphere.

Raw material is released from the hopper H] as desired by means of a feeding device comprising a stainless steel disk-like gate 24. This gate, comprising two slightly warped semicircular metal sheets, is carried on a rod 26 that extends through the Wilson seal l6 and is operated by a handwheel 28. A cylindrical rod made of onequarter inch stainless or ordinary carbon steel stock is suitable. Rotation of the handwheel 28 produces rotation of the gate 24 which thereupon functions like a feed screw to release material from the hopper in a conventional manner.

The hopper I0 is connected to a subliming container o1- kiln 30 by means of a duct 32, through which the raw material is delivered by gravity when released by the gate 24. Ordinarily, the container 30 is a 2.25 inch diameter Pyrex glass cylinder about 50 inches long. The containerv 30 has two downwardly extending delivery ducts or tubes 34 and 35. The sublimed and purified material is transmitted to a storage receptacle 38 through the tube 35, and unsublimed material is moved through the tube 34 to a'receptacle 40 connected thereto at 42. The container 30 also has tubular extensions 44, 46 and 48 constituting portals for the devices that manipulate materials being processed, as well as two ducts 50 and 52, located exteriorly of the path of material as it is processed, for connections to apparatus capable of producing a vacuum of at least10 mm. Hg. A gas-tight joint 54 is provided to facilitate assembling and cleaning the apparatus.

Near its center the horizontally disposed container 30 has a subliming zone surrounded by a furnace 56. This furnace consists of two semicyli'ndrical electrical resistance heaters 58 and 60, capable of raising the mass of material being processed to its volatilization and/ or decomposition temperature. The temperature commonly employed in subliming uranium hexachloride in this apparatus is about 150 to 180 C., or even as high as 210 C. The heaters have individual electrical connections 62 and 64 for a source of heating current. The heater sections are constructed to provide space for a thermocouple well 66. The thermocouple therein (not shown) is connected by conductors 68 and 10 to an indicating and/or recording instrument 12, such as a potentiometer or voltmeter, which may be suitably calibrated to indicate and/0r record directly in terms of the temperature prevailing within the subliming zone.

For moving material inside the vessel 30 at the feeder end thereof, an implement comprising a rod if. carrying a chisel l6 and a hoe 18 is provided. To insure adequate rigidity, this rod should be about one-quarter inch in diameter. The rod 74 extends through a conventional Wilson seal in the tubular extension 44, and carries on its external end a handwheel 82 by which the implement. is manipulated. The chisel l6 and hoe 78 are ordinarily made of stainless steel. The hoe is preferably in the form of an approximately 120 helical sector, tilted at an angle of about 225 to a. plane normal to the axis of the rod, so that by rotating the rod E4 the hoe can be screwed into the mass of granular material in the chamber without pushing the entire mass of material forward, thus breaking up lumps or aggregates of the material.

For testing the gastightness of the connection around the rod 1'4, the Wilson seal 80 has, as is usual with these devices, a lateral tube 84 for connection to vacuum-producing apparatus.

At the delivery end of the container 30, in the tubular extension 46, there is another material manipulating arrangement comprising a rod 86 carrying a chise1 88 and a scraper blade 90, a surface of which is substantially normal to the axis of the rod. As clearly shown in Figs. 1 to 4, the chisel portion 88 comprises one chisel surface 92 adapted to contact more or less closely the wall surface of the chamber 30 in order to scrape sublimate therefrom, and a second chisel surface 94 extending ahead of, and substantially at right angles to, the first-mentioned chisel surface 92, thereby functioning to split portions of the sublimate away from the main bulk thereof before the first-mentioned chisel surface 92 can develop a wedge action upon the main mass of sublimate when the tool is driven in a direction generally parallel to the wall surface. It will also be noted that the second-mentioned chisel surface 94 slopes with respect to the axis of the rod, forming a relatively sharp trihedral angle at the outermost point, which point (as shown in Fig. 3) lies somewhat below the plane of the first-mentioned chisel surface 92, the whole thereby forming an extremely effective chisel.

The rod extends through an improved Wilson seal 96 and carries, exteriorly of the container 30, a handwheel 98 by which it is manipulated. This rod is also preferably of one-quarter inch round stock. The diaphragm case or holder of the Wilson seal carries the customary vacuum connection tube I00.

The improved Wilson seal 96 preferably employed in conjunction with rod 86 is of a new design, being specially constructed to allow more than the usual (12) reflection for the rod 86, as is customary in the conventional Wilson seal, such as seal 80. This improved Wilson seal is fully described in the U. S. Patent 2,442,622 to Starr issued June 1, 1948. For specific details of this improved Wilson seal reference may be had to the aforementioned Starr patent, it being sufficient for present purposes to note in passing that the greater range in movement afforded by this seal is obtained by an arrangement including a swivel joint. This joint, located between the case carrying the diaphragms (not shown) and the plug fitting into the extension 46, is covered by a conventional flexible thin metal bellows I02. This bellows is soldered to the aforementioned parts to permit maintaining the high vacuum inside the apparatus.

The tubular extension 48 extending upwardly from the container 30 carries a conventional Wilson seal 14, incorporating a vacuum testing connection tube I06. A rod 108, which extends through the Wilson seal 04, has a pointed and/or notched end H0 and carries adjacent thereto a small hook I I2 pointing in substantially the opposite direction, This rod is conveniently made from one-eighth inch round stock. A handwheel H4 at the external end of the rod I08 is utilized for imparting movement thereto.

Referring now to Fig. 8, the duct 36 projects into a hood I30 and terminates in a nozzle I32 which is surrounded by a telescoping spout I34. During the time the storage receptacle 38 is being filled, this spout projects into the mouth of the receptacle and is supported on the top of the receptacle by an integral, laterally projecting flange I36. This arrangement forms a continuous passage, whereby material falling through the duct 36 is conducted into the interior of the receptacle, thereby avoiding an accumulation of material in fine particle or dust form on the top of the receptacle adjacent the closure, which accumulation of material would interfere with sealing the closure.

The hood I33 comprises a flange I38 conforming to the top of the receptacle 36 and a laterally extending tubular portion I40 that forms the housing for a rod I42 that is supported within a conventional Wilson seal i4 3. This rod, preferably of one-quarter inch round stock, is manipulated by a handwheel I46 and carries on its inner end a hook I 48 which, during the receptacle filling operation, supports a cap I50 for the receptacle 36 in a position within the lateral extension M0 where the cap cannot interfere with the descent of material into the storage receptacle (Fig. 1 position). The hook H2 on the rod I03 supports the telescopic spout I34 above the mouth of the receptacle 36 during the receptacle capping operation (Fig. 8 position).

The conventional Wilson seal I 44 that closes the tubular extension I40 is typical of the conventional Wilson seals that have been referred to hereinbefore, and consequently will be described in some detail for the sake of completeness. This seal comprises a plug portion I68 having a seat upon which a rubber diaphragm I62 is supported. A circular and annular spacer I64 engages the diaphragm I 62 and, in turn, is engaged by a secand rubber diaphragm I66. This assembly is maintained in position by a washer I68 and-a screw plug I10. A vent I12 in the annular portion of the spacer I64 connects the space between the rubber diaphragms I62 and I66 to a tube I14. This tube I14 is employed as a vacuum connection for testing the adequacy of the seal made between the rod I42 and the two cooperating diaphragms I62 and I66. By evacuating the tube I14, it is possible to determine before the processing of material is started whether or not a gastight seal between the rod I42 and the plug I60 is formed by either or both of the diaphragms I62 and I 66.

The receptacle 38 is cylindrical in shape and has a circular mouth I80 in the top. Surrounding the mouth is a groove I82 designed to receive the depending skirt or flange I84 of the cap I50, and a groove I86 for packing purposes. Ordinarily, the mouth I80 and grooves I82 and I66 are located concentrically in the top of the receptacle. An annular gasket I88, preferably made of rubber, is positioned in the groove I86 in order to produce a vacuum-tight seal between the receptacle 38 and the hood I30. Preferably, the receptacle 38 is made of stainless steel, for example, 18-8 (18-Cr, 8-Ni; U. S. S. #316) stock, but other metals not readily attacked by the vapors of uranium halides may be used if desired.

While being filled and closed the receptacle 38 is secured to the hood I30 by a cage-like frame 200. This frame comprises a split ring that grips the receptacle 33 and a split collar that extends over the flange I 38 on the hood I30. The split ring is indicated by the reference numeral 202 and the split collar by the reference numeral 204. The split ring is held in gripping engagement with the receptacle 38 in a manner that will be apparent upon inspection of Figs. 1 and 8, and is in turn secured to the split collar 204 that supports the entire assembly in gastight relation against the flange I38 of the hood I30 in a manner that likewise will be apparent upon inspection of these figures. A fiat ring 206, preferably made of rubber, serves as a cushion between the split collar 204 of the frame 200 and the frangible flange I38 of the hood E30. Further specific details of this assembly are not pertinent to the present claimed invention, but may be obtained by consulting the above-mentioned prior copending application Serial No. 552,556.

The method of completing the appropriate seal between the cap I50 and the mouth of receptacle 38 is fully described in the above-mentioned prior copending application Serial No. 552,556. Since this subject matter forms no part of the present claimed invention, it is deemed unnecessary to describe it in detail at this point, it being suffioient to note in passing that the cap I50 removably supports an electric heater 2| 0, the heater 2| 0 being secured in place by an arrangement including a screw 2I2 threaded into the cap I50. The heater includes an electric resistance element, one terminal of which is grounded to the cap I50 and the other terminal of which is connected to a terminal post 254 in the form of a loop or eyelet. The circuit for the heater element may be completed (in a manner not shown) by setting the notched end H0 of the rod I 08 against the loop 2H3, and by connecting the rod I08 and the receptacle 38 to a suitable current source bya circuit having a suitable switch (not shown) for making. and breaking the heater circuit.

Considering now the mode of operation of the apparatus shown in Figs. 1 to 8, the hopper I is filled with a mass of raw or crude hygroscopic material 300 (such as uranium hexachloride) in subdivided form through the conduit I2, and the plug 22 is fitted into the end of the conduit I2 in gastight relation. A quantity of glass 01' other relatively inert material 302, in the form of powder or small beads, is placed in the container 30 in a position from which it can be later advanced toward the subliming zone for a purpose to be noted more fully hereinafter; a previously prepared receptacle cap I50 is suspended upon the hook I48 carried by the rod I42 in the tubular extension I40; a previously prepared storage receptacle 38 is secured and sealed to the hood I30 by the frame 200, the telescopic spout I34 being adjusted in the mouth I80 of the storage receptacle 38; the receptacle 40 is secured to the tube 34; and the joints 42 and 54 are closed. Preferably, the joints 42 and 54, as well as the connections between the conduit I2 and the plug 22 are sealed in a gastight manner with ordinary sealing wax. Similarly, the connection between the tubular extension I4 and the Wilson seal IS, the connection between the tubular extension 44 and the Wilson seal 80, the connection between the tubular extension 46 and the Wilson seal 83, the connection between the tubular extension 48 and the Wilson seal I04, and the connection between the tubular extension I40 and the Wilson seal I44 are also sealed with sealing wax. The vacuum-testing tubes I8, 84, I00, I06 and I14, respectively associated with the Wilson seals I3, 80, 96, I04 and I44 are suitably connected to the vacuum-producing apparatus and the several Wilson seals are tested in order to insure that the apparatus as a whole is gastight. The ducts 20, 50 and 52 are then connected to the vacuumproducing apparatus, whereby the container 30 and the connected parts are evacuated to a relatively low pressure, such for example as l0 mm. Hg.

A portion of the crude uranium hexachloride 300 is introduced into the container 30 by suitably rotating or reciprocating the handwheel 28 in order to control the gate 24, and is positioned in the heating zone within the furnace, as shown at 304, by means of the hoe I8. Thereafter the subdivided glass or other relatively inert material 302 is spread over the adjacent or feed side of the pile of crude uranium hexachloride, as shown at 306, thereby preventing or substantially preventing the fiow of vapors toward the feed side of the apparatus. Heat is then applied, causing volatilization of the uranium hexachloride, the vapor of which flows toward the cooler portion of the container 30 and condenses thereon, as shown at 308. Accordingly, it will be noted that the portion of the container lying between the heater 50 and the duct 48 functions as an air-cooled condenser; it may be additionally noted that, when and if desired, supplemental cooling structure, such as a surrounding coil (not shown) through which is circulated a cooling medium such as water, may be provided at this point.

The condensate of uranium hexachloride usually begins to appear when the charge has reached a temperature of approximately 80 C. However, temperatures somewhat in excess of 150 C., for example in the range of approximately 150 to 190 C., are preferred for the sublimation of this material at a practicable rate. The sublimation of the UCls may be carried to substantial completion by raising the temperature to about 210 C. for a short time (up to about thirty minutes) at the end of a run at the lower temperature mentioned. The use of the higher temperature for extended periods is ordinarily not desired because uranium hexachloride begins to decompose slightly at C., and at an appreciable rate above C. in vacuo.

The layer of glass 306 serves to retard or prevent the fiow of volatilized uranium compound in the opposite direction. When the vaporization of the charge has been completed, the glass and residual matter from the charge is raked back and into the receptacle 40 as shown at 3I0, except for a portion which preferably is retained in the tube 30 between ducts 32 and 34 to serve as a vapor blocking layer for the succeeding mass of crude material to be processed. Another portion of the crude material 300 is then admitted to the tube 30 from the hopper I0 and is positioned in the heating zone at 304, after which it is covered with a layer 306 of subdivided glass and nonvaporized material from a previous run or runs, and another vaporization cycle is conducted. These cycles are then repeated without breaking vacuum until the supply of crude uranium hexachloride 300 has been exhausted.

The condensed uranium hexachloride 308 that collects on the cooler portions of the wall of the container 30 is chiseled away, preferably after each sublimation, with the chisel 88 and raked into the duct 36 with the hoe 90. The sublimate is deposited on the inside of the tube 30 in a zone ordinarily extending from about one-half inch to twelve inches from the edge of the hot zone, with the thickest deposit usually occurring in the first three inches. The uranium hexachloride that sublimes below C. condenses in this three-inch zone in a layer usually about %-inch thick. This deposit has a mechanical strength approximately equal to that of anthracite coal and hence must be chiseled off the wall. However, the adhesion between the deposit and the glass is somewhat weaker than its internal strength or cohesion, so that the deposit tends to scale or break off in large pieces, particularly when the wall surface of the container 30 is clean. For this reason it will be apparent that the chisel 88 comprising the forward cutting edge 94, tending to break oif the deposit in the form of smaller pieces before large pieces scale 01f the container wall, is of particular advantage in handling material of this character. Pieces too large to pass through the duct 36 may be chopped into smaller pieces by means of the pointed end III! of the rod I08.

Although by this method all of the sublimed and purified uranium hexachloride may not be completely removed from the wall of the container 30, and although some slight amount of uranium hexachloride vapor may have seeped through the barrier layer 306 and deposited in solid form in the feed end of the tube 30, it is unnecessary to clean the tube after each run since dry air (which may be introduced into the apparatus when fesh feed material is introduced into the hopper I0 and which might remain in extremely small amount in the apparatus) causes no visible decomposition of the uranium hexachloride. It is therefore customary practice to clean the entire apparatus only after a number of runs.

A single run of the type described above usually requires a full working day and produces approximately one-half kilogram of highly purified uranium hexachloride, these figures being exemplary and based upon the particular apparatus chosen by way of illustration.

Instead of treating an impure uranium hexachloride to obtain the desired highly purified uranium hexachloride product as described above, uranium pentachloride may be employed as the starting material for the production of uranium hexachloride by the reaction mechanism disclosed in the copending application of Francis A. Jenikins, Serial No. 494,447, filed July 13, 1943; i. e., by the disproportionation of uranium pentachloride into uranium hexachloride and uranium tetrachloride under the influence of heat. When uranium pentachloride is used as the starting material 300, it is heated in the subliming zone to a temperature ranging from about 80 to about 180 C., but preferably toward the upper end of this range. Temperatures as high as 250 C. may be employed for short periods, 50 as not to cause undue decomposition of the produced uranium hexachloride. At such temperatures, and under high vacuum, the uranium pentachloride is decomposed into uranium tetrachloride and uranium hexachloride, the latter passing out of the heated zone in the form of vapor which is condensed in the cooler portion of the container 30 from which it is removed and loaded into the storage receptacle 38, as more fully described above. A residue,

mainly uranium tetrachloride, of over 50 per cent of the original material is left in the sublimation zone. As this residue accumulates in the sublimation zone during and as a result of the disproportionation of successive charges of uranium pentachloride and the attendant vaporization of uranium hexachloride produced thereby, the undesired accumulation of residue is raked into the duct 34 and collected in the receiver 40 at desired intervals for suitable salvage operations, preferably however retaining each time sufficient of the residue in the container 30 to serve as a blocking layer 336 for the succeeding charge. of uranium pentachloride that is positioned in the subliming zone at 305.

Uranium tetrachloride of more or less impure form may also be used as the starting material 300 where it is desired to prepare and/or package this compound in a highly purified form for subsequent use. In this case the operation of the apparatus is generally similar to that already described for the case of uranium hexachloride, except that considerably higher temperatures, such as 512 to 520 C., are preferably employed for subliming the uranium tetrachloride since this compound is considerably less volatile than uranium hexachloride. In general, a temperature of at least 500 C. is preferably employed. Condensation of purified uranium tetrachloride in the cooler portions of the tube 30 is ordinarily first observed at a temperature of about 365 to 380 C., under the pressure conditions already set forth. However, temperatures of from approximately 500 to 550 C. or higher are required for the sublimation of this material at a practicable rate. When these higher temperatures are employed it may be desirable to employ additional support for the tube 30 to prevent any sagging of the tube due to the higher temperatures necessary for the sublimation of uranium tetrachloride at practicable rates.

It will be understood that when a sufiicient quantity of sublimate of highly purified uranium hexachloride (or of highly purified uranium tetrachloride, when the starting material 300 comprises more or less impure uranium tetrachloride as described in the preceding paragraph) has been deposited on the walls of the container as shown at 308, the deposit is removed from the walls, broken into sufiiciently small particles to pass through duct 36, and scraped into the duct by suitable manipulation through the corresponding seals of rod 86 carrying scraper 90 and chisel 88 and rod I08 having the pointed end IIO. In this manner sufiicient purified sublimate is collected to fill the storage receptacle 38 to the desired level. Where two or more sublimation cycles are required to obtain the desired quantity of sublimate, care is taken to maintain the vacuum in the system between successive cycles, as previously mentioned.

Having collected the desired quantity of purified sublimate in the storage receptacle 38, the rod I00 is manipulated so that hook II2- lifts the telescopic spout I34 from the filling position shown in Fig. 1 to the capping position shown in Fig. 8, the rod I42 with its hook I48 carrying the cover I523 is manipulated to move the cover from its retracted filling position shown in Fig. 1 to the position shown in Fig. 8, and the cover is thereupon placed in capping position with its skirt I84 disposed in groove I82 of the receptcale 38. (It will be understood that the groove I82 in the top of the storage receptacle 38 and the skirt I84 of the cap I56 will have been prepared previously for the soldering operation, in, the manner fully described in the prior copending application Serial No. 552,556.) Rod I42 is then manipulated so that its hook I48 supports the telescoping spout I30, thereby freeing rod I08 with its pointed end I II] for another purpose, namely, that of completing the electric circuit to the receptacle cap heater 2H For this purpose the rod I08 is manipulated so that its notched end H0 bears firmly upon the eyelet 2I4 that forms a terminal post for the resistance element of the heater ZIII that is attached to the cover I50. Upon completing the electrical circuit including the heater 2 I B, the latter is energized and thereby supplies sufficient heat to the cap I50 to melt a mass of solder, such as Woods metal, that is employed to hermetically seal the cap I50 to the receptacle S8. The circuit is then opened and, after cooling, the Woods metal forms a hermetic seal between the skirt I84 of the cover I50 and the top of the storage receptacle 38. The frame 200 by which the receptacle 38 is clamped against the flange I38 of the hood I30 may then be unfastened, and the storage receptacle 38 with its hermetically sealed contents removed from the apparatus. Another receptacle cover or cap I50 and another storage receptacle 38 (previously prepared for the soldering operation) may then be placed in position in the apparatus, and the purifying and sealing operations resumed.

The vacuum-producing device associated with the purifying and packaging apparatus of Figs. 1 to 8 has not been shown in detail since it will be understood that it may be purely conventional in nature. Thus, this device preferably comprises two liquid air traps and a mercury diffusion pump. In addition, it is preferable to include drying tubes provided with magnesium perchlorate and phosphorus pentoxide to dry the stream of air entering the apparatus when it is let down to atmospheric pressure. I

When processing corrosive materials such as are described herein, it is desirableparticularly in view of the relatively elevated temperatures employed-to use specially selected materials of 11 construction for the apparatus. Because of its heat resistance, Pyrex glass is the preferred material for constructing the principal parts of the apparatus. The rods 26, I4, 86, I08 and I42, the hoes I8 and 90, the hooks H2 and I48, and the storage receptacle 38 are preferably made of stainless steel stock, such as 18-8 (Cr-18, Ni-8; U. S. S. #316), in order to resist corrosion by chlorine-containing materials inside the apparatus. The chisels or spikes I6 and 88 are made of tool steel. The receptacle cap I50 may be made of soft iron, and, since soft iron is not easily wet by molten Woods metal (the material ordinarily used for soldering the cap to the storage receptacle), it is desirable'that the skirt I84 on the cap I50 be coated or tinned with a metal that is readily wet by such an alloy, for example, a noble metal such as silver, gold, platinum, iridium or osmium. For like reasons, it is preferable also to coat the interior of the groove I82 with a layer of wetting metal, such as one of the noble metals just mentioned. The Woods metal referred to above is a very low-melting material, usually the quaternary alloy 50 Bi, 2'5 Pb, 12.5 Sn and 12.5 Cd. This substance melts at 655 C. A silver solder comprising 63 Ag, 30 Cu and 7 .5 Zn is especially suitable for tinning the skirt I84 on the cap I50.

While the foregoing apparatus has been described in connection with a process for treating certain named uranium compounds, it will be obvious that it is not limited to use with such materials. It will be especially obvious that the adjuvant apparatus elements to which the claims herein are particularly directed are of wide application, and that they will be found to be well adapted for processing other materials in Vacuo where it is necessary to move the materials undergoing processing from without the apparatus, without at the same time disturbing the vacuum conditions within.

Probably many apparently widely different embodiments of this invention may be made without departing from the principle, breadth and spirit thereof and it is to be understood, therefore, that this invention is not limited to the 12 specific embodiments thereof except as encompassed in the following claims.

What isclaimed is:

1. For use in a vacuum filling apparatus having a processing chamber, a container loading chamber, a reduced diameter nozzle extending from said processing chamber into said loading chamber and provided with a loosely surrounding movable sleeve adapted to guide material from the nozzle through the container loading chamber; an improved guiding means for solid materials including, an elongated rod mounted intermediate its ends in vacuum sealing relation to said processing chamber for selective longitudinal and rocking motion, said rod having at one end a sharp point adapted to break solid materials, a curved hook attached to said rod adjacent s id pointed end and extending toward the opposite end of said rod, and a manipulating means attached to said rod exteriorly of said sealing location whereby upon longitudinal and rocking movement of said rod with the pointed end adjacent the junction of the nozzle and processing chamber larger pieces of solid material may be broken by the pointed end and agitated by the hook thereby to guide the material into said nozzle and upon longitudinal and rocking movement of the rod with the curved hook adjacent the movable sleeve an engagement of rod and sleeve may be effected.

2. Apparatus as described in claim 1, wherein said rod is composed of stainless steel material. CHARLES H. PRESCOTT, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

1. FOR USE IN A VACUUM FILLING APPARATUS HAVING A PROCESSING CHAMBER, A CONTAINER LOADING CHAMBER, A REDUCED DIAMETER NOZZLE EXTENDING FROM SAID PROCESSING CHAMBER INTO SAID LOADING CHAMBER AND PROVIDED WITH A LOOSLEY SURROUNDING MOVABLE SLEEVE ADAPTED TO GUIDE MATERIAL FROM THE NOZZLE THROUGH THE CONTAINER LOADING CHAMBER; AN IMPROVED GUIDING MEANS FOR SOLID METERIALS INCLUDING, AN ELONGATED ROD MOUNTED INTERMEDIATE ITS ENDS IN VACUUM SEALING RELATION TO SAID PROCESSING CHAMBER OF SELECTIVE LONGITUDINAL AND ROCKING MOTION, SAID ROD HAVING AT ONE END A SHARP POINT ADAPTED TO BREAK SOLID MATERIALS, A CURVED HOOK ATTACHED TO SAID ROD ADJACENT SAID POINTED END AND EXTENDING TOWARD THE OPPOSITEE END OF SAID ROD, AND A MANIPULATING MEANS ATTACHED TO SAID ROD EXTERIORLY OF SAID SEALING LOCATION WHEREBY UPON LONGITUDINAL AND ROCKING 